Methods for assessment of pelvic organ conditions affecting the vagina

ABSTRACT

Methods for assessment of pelvic floor conditions based on tactile imaging are described. The vaginal wall is deformed using a transvaginal probe equipped with tactile pressure sensors and a motion tracking sensor. The vaginal wall coordinates and pressure patterns are obtained during the examination and used to build 3-D tactile image of the vagina and to calculate elasticity modulus profiles and spacing profiles along selected lines inside 3-D tactile image. The profile values at specified locations are then compared with thresholds or profiles for normal conditions of vagina and its support structures. Methods of the invention are disclosed to be used in assessing a risk of pelvic organ prolapse development, estimating an extent of pelvic floor organ traumatic damage after childbirth and estimating an improvement after an interventional procedure.

CROSS-REFERENCE DATA

This application claims a priority benefit from a U.S. patentapplication Ser. No. 12/874,583 filed 2 Sep. 2010 entitled “Methods forcharacterizing vaginal tissue elasticity”, which in turn is a regularapplication filed based on a U.S. Provisional Patent Application No.61/239,087 filed 2 Sep. 2009 entitled “Methods of using a vaginaltactile imager for pelvic organ prolapse characterization, includingthat after a reconstructive surgery”, both of which are incorporatedherein in their respective entireties by reference.

REFERENCE TO GOVERNMENT-SPONSORED RESEARCH

This invention was made with the U.S. government support under SBIRgrant No. AG034714 entitled “Vaginal Tactile Imager for Pelvic FloorBiomechanical Assessment” and awarded by the National Institute ofHealth, National Institute on Aging. The government has certain rightsin this invention.

FIELD OF THE INVENTION

The present invention generally relates to methods for characterizationof pelvic floor organs and support tissues. More specifically, theinvention describes methods for assessment of pelvic organ conditionsaffecting the vagina such as pelvic organ prolapse, childbirth traumaand reconstructive surgery in women.

BACKGROUND OF THE INVENTION

Pelvic organ prolapse (POP) is the descent of the apex of the vagina,including the cervix (or vaginal vault after hysterectomy), anteriorvaginal wall, and/or posterior vaginal wall. As prolapse progresses,pelvic organs may become displaced and even protrude outside the vaginalcanal. POP is a highly prevalent condition affecting at least 50% ofwomen in the US during their lifetimes. In fact, some loss ofutero-vaginal support occurs in most adult women. POP is the leadingindication for hysterectomy in postmenopausal women and accounts for15-18% of procedures in all age groups [Kesharvarz H, Hillis S D, KiekeB A, Marchbanks P A. Hysterectomy surveillance—United States 1994-1999.MMWR Surveill Summ 2002; 51 (SS05):1-8]. Overall, 1 in 10 women willundergo surgery to treat pelvic floor support conditions in the courseof their lifetime. This number is projected to significantly increasewith the anticipated growth of the aging population in the UnitedStates. Beyond the physical impact of POP, women with progressing pelvicorgan prolapse score poorer on both general and condition-specificquality-of-life scales [Jelovsek J E, Barber M D. Women seekingtreatment for advanced pelvic organ prolapse have decreased body imageand quality of life. Am J Obstet Gynecol 2006; 194: 1455-1461]. Inaddition, about one third of sexually active women with POP report thattheir condition interferes with sexual function [Barber M D, Visco A G,Wyman, et al. Sexual function in women with urinary incontinence andpelvic organ prolapse. Obstet Gynecol 2002; 99:281-289].

Women with symptomatic POP who fail or decline conservative management,including pessary use and physical therapy treatment, are candidates forreconstructive surgery. The overall goal for prolapse surgery is to givethe most functional repair, while preventing recurrence of the conditionand minimizing complications incurred by these repairs. Recurrence isone of the barriers in surgical correction most frustrating to both thesurgeon and patient. Failure rates as high as 20-40% have been citedafter surgical repair, with over 50% occurring within the first threeyears [Clemons J L, Myers D L, Aguilar V C, Arya L A. Vaginalparavaginal repair with an AlloDerm graft. Am J Obstet Gynecol 2003;189(6):1612-1618]. Since many patients with POP have inherentlydeficient or defective connective tissue, to minimize recurrence of POPmany reconstructive surgeons have turned to the use of adjuvantmaterials for vaginal support. Such materials may include synthetic,allogenic, xenogenic or autologous grafts [Bako A, Dhar R. Review ofsynthetic mesh-related complications in pelvic floor reconstructivesurgery. Int Urogynecol J Pelvic Floor Dysfunct 2009; 20(1):103-111].Currently, at least 10 synthetic materials are available for vaginal use[Sung V W, Rogers R G, Schaffer J I, et al. Graft Use in TransvaginalPelvic Organ Prolapse Repair: A Systematic Review. Obstet Gynecol 2008;112(5):1131-1142]. Unfortunately, none of the currently available graftmaterials is ideal for restoration of both optimal support andfunctionality of the vaginal walls.

When determining the etiology of POP and delineating risk factors forPOP, parity has the strongest association with risk of requiring surgeryfor POP, Pregnancy and childbirth have a tremendous impact on women'svaginal connective tissue, nerves and muscles support within the pelvisdue to prolonged pressure, straining and distention forces that areplaced on the pelvic tissues. Traumatic changes of the pelvic floor areencountered during childbirth including avulsion of muscle from thesupporting bony structure of the pelvis, damage to vaginal supportligaments and muscle atrophy after pelvic nerve damage. Pelvic floordysfunction, in the form of pelvic floor prolapse (including cystocele,rectocele, enterocele and uterine prolapse) and urinary and fecalincontinence are considered inevitable sequelae for some women whoexperience injuries during childbirth. Compared with nulliparous women,women with one child were 4 times more likely (and those with twochildren were 8.4 times more likely) to develop pelvic organ prolapserequiring hospital admission and surgical intervention. With theburgeoning elderly population, the latent injuries caused in childbirthwill affect more and more women later in life. Although surgery forpelvic organ prolapse is effective in restoring anatomy, functionaloutcomes have not been as satisfactory and there are many questionsregarding underlying biomechanical properties of the pelvis that arecurrently poorly defined to guide optimal repair.

Pelvic floor organs and support structures are elements of abiomechanical system providing critically important set of physiologicalprocesses. Despite the obvious fact that POP and childbirth damages arecaused by structural failures, only recently researchers have begun toconduct a biomechanical analysis of the mechanisms of normal pelvicorgan support and failure.

A critical review of published data on the urogynecologic aspects offemale sexual dysfunction demonstrates a lack of standardizedinstruments for assessing biomechanical conditions of the pelvic floor.There is a need in 3-D imaging of vagina and its surrounding structuresand reproducible measurements of vaginal tissue elasticity in-vivobecause the tissue elasticity, as a capability to hold load andreversely undergoing to elongation, is the primary mechanicalcharacteristic.

The high incidence of POP, childbirth damages and the rate ofreconstructive surgery dictate the need for new effective methods forassessment of pelvic organ conditions after reconstructive surgery orother interventional procedures in women. Elasticity imaging of thevagina after reconstructive surgery may allow to quantitativelycharacterize the effectiveness of the surgical approach and behavior ofmaterials used for vaginal support in-vivo.

Elasticity Imaging and Assessment of Soft Human Tissues

In the last decade, a new modality for tissue characterization hasemerged termed Elasticity imaging or Elastography. Elasticity imagingallows visualization and assessment of mechanical properties of softtissue. Mechanical properties of tissues, i.e. elastic modulus andviscosity, are highly sensitive to tissue structural changesaccompanying various physiological and pathological processes. A changein Young's modulus of tissue during the development of pathologicalprocesses could reach hundreds and even thousands of percent (A. P.Sarvazyan. “Elastic properties of soft tissue”, In: Handbook of ElasticProperties of Solids, Liquids and Gases, Volume III, Chapter 5, eds.Levy, Bass and Stern, Academic Press, 2001, pp. 107-127.). Elasticityimaging is based on generating a stress in the tissue using variousstatic or dynamic means and then measuring resulting strain(displacements in volume) with the use of ultrasound or magneticresonance imaging. Tactile imaging yields a tissue elasticity mapsimilar to other elastographic techniques. At the same time, tactileimaging, unlike strain imaging, uses stress or pressure data on thesurface of tissue under applied load. It mimics manual palpation,because a tactile imaging probe with a pressure sensor array mounted onits face acts similarly to a human finger during a clinical examinationby compressing soft tissue with the probe and detecting resultingchanges as a surface pressure pattern.

SUMMARY OF THE INVENTION

The object of the present invention is to overcome the drawbacks of theprior art and provide methods for quantitative and reproducibleassessment of pelvic organ conditions affecting the vagina, includingmethods for estimating a risk of pelvic organ prolapse development.

Another object of the invention is to provide methods for characterizingtraumatic conditions of pelvic floor structures after childbirth.

A further yet object of the invention is to provide methods forpost-operative assessment of pelvic floor conditions.

The present invention involves tactile imaging and assessing tissueconditions affecting a vagina. In general, the present inventionachieves this by obtaining pressure patterns and respective coordinatesforming together a tactile image of the vagina and then calculatingtissue elasticity and anatomy of vaginal structures therefrom.

In embodiments, methods for assessment of pelvic organ conditionsaffecting a vagina such as a risk of pelvic organ prolapse developmentmay include the following steps:

(a) conducting examination of vagina by deforming vagina along ananterior vaginal wall and along a posterior vaginal wall using atransvaginal probe;(b) obtaining pressure patterns and coordinates corresponding theretofor portions of vagina examined with the transvaginal probe;(c) calculating at least one or both anterior elasticity modulus profileand posterior elasticity modulus profile, these elasticity modulusprofiles being defined by at least two or more locations spaced apart inthe respective portion of vagina examined with the transvaginal probe;(d) calculating at least two or more distances between the anteriorvaginal wall and the posterior vaginal wall along the vagina whichcumulatively define a spacing profile of the vagina; and(e) estimating a risk of pelvic organ prolapse development by comparingat least one elasticity modulus profile at the two locations againstrespective predetermined elasticity modulus thresholds for the same twolocations as well as by comparing the spacing profile against respectivepredetermined distance thresholds.

In embodiments, a similar approach may be taken for assessment of otherconditions affecting vagina, such as extent of pelvic support tissueimpairment or damage after childbirth or an improvement after aninterventional procedure such as surgery for example. Measuredelasticity and geometrical parameters such as spacing profiles may becompared to predetermined normal values obtained for a plurality ofpatients with known clinical history or may be compared for each patientindividually using results of previous examinations.

The details of embodiments of the invention are set forth in theaccompanying drawings and the description below. Other features,objects, and advantages of the invention will be apparent from thedescription, drawings and from the claims.

BRIEF DESCRIPTION OF DRAWINGS

Subject matter is particularly pointed out and distinctly claimed in theconcluding portion of the specification. The foregoing and otherfeatures of the present disclosure will become more fully apparent fromthe following description and appended claims, taken in conjunction withthe accompanying drawings. Understanding that these drawings depict onlyseveral embodiments in accordance with the disclosure and are,therefore, not to be considered limiting of its scope, the disclosurewill be described with additional specificity and detail through use ofthe accompanying drawings, in which:

FIG. 1 illustrates a procedure of examining the vagina with atransvaginal probe;

FIG. 2 shows an example of transverse, sagittal and coronalcross-sections of a 3-D tactile image of a normal vagina;

FIG. 3 shows an example of transverse, sagittal and coronalcross-sections of a 3-D tactile image for a vagina with confirmed pelvicorgan prolapse;

FIG. 4 shows an example of calculated elasticity modulus profiles forthe anterior and posterior vaginal walls;

FIG. 5 shows an example of calculated spacing profile for theanterior-posterior vaginal walls;

FIG. 6 is a flow chart illustrating a method for assessment of pelvicorgan conditions affecting the vagina which includes the step ofestimating a risk of vaginal organ prolapse development;

FIG. 7 is a flow chart illustrating a method for assessment of pelvicorgan conditions affecting the vagina which includes the step ofestimating traumatic damage after childbirth;

FIG. 8 is a flow chart illustrating a method for assessment of pelvicorgan conditions affecting the vagina which includes the step ofestimating an improvement after the interventional procedure.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION

The following description sets forth various examples along withspecific details to provide a thorough understanding of claimed subjectmatter. It will be understood by those skilled in the art, however thatclaimed subject matter may be practiced without one or more of thespecific details disclosed herein. Further, in some circumstances,well-known methods, procedures, systems, components and/or circuits havenot been described in detail in order to avoid unnecessarily obscuringclaimed subject matter. In the following detailed description, referenceis made to the accompanying drawings, which form a part hereof. In thedrawings, similar symbols typically identify similar components, unlesscontext dictates otherwise. The illustrative embodiments described inthe detailed description, drawings, and claims are not meant to belimiting. Other embodiments may be utilized, and other changes may bemade, without departing from the spirit or scope of the subject matterpresented here. It will be readily understood that the aspects of thepresent disclosure, as generally described herein, and illustrated inthe figures, can be arranged, substituted, combined, and designed in awide variety of different configurations, all of which are explicitlycontemplated and make part of this disclosure.

In embodiments, methods for the assessment of pelvic organ conditionsaffecting the vagina employs a deformation of vaginal walls by manuallyoperated transvaginal probe with incorporated pressure sensor arrays andmotion tracking sensor. A number of pressure sensor coordinates in acoordinate system adapted for women pelvic floor together withcorresponding pressure sensor signals are used to generate 3-D tactileimages of the vagina. The tissue elasticity, such as for examplerepresented by Young's modulus (E), may be calculated from spatialgradients obtained from a 3-D tactile image in the region of interest.Such elasticity modulus may be calculated in one spot or along aspecified line forming an elasticity modulus profile. This approach wasvalidated with multiple pelvic floor models built with two-componentsilicone having known predetermined elasticity distribution.Reproducibility of elasticity measurements with resolution better than7% and accuracy within 20% for the tissue elasticity range between 2 kPaand 50 kPa was established after operators passed through a trainingprogram using pelvic floor models. In comparison with this broad rangeof elasticity, a capacity of human finger to scale the magnitude ofsoftness of objects is substantially lower (Friedman R M, Hester K D,Green B G, LaMotte R H. Magnitude estimation of softness. Exp Brain Res2008; 191:133-142.). This points out to a substantial advantage of usingthe methods of the invention in place of manual examination.

Referring now to FIG. 1, a procedure of a vaginal examination isillustrated. The examination may be performed on patient in a standardposition suitable for physical examination of the vagina in agynecologic office. During examination, the transvaginal probe 10 may beprotected by a disposable elastic sheath covered with a lubricant. Thetransvaginal probe 10 may be placed into vagina 11 and used to deformthe vaginal wall by applying a pressure load thereto. In embodiments, anexemplary examination technique includes sequential compressions of theposterior vaginal wall 17 by the probe 10 from the proximal to distalpart of the vagina to collect the data along the posterior vaginal wall,allowing visualization of the posterior part of vagina in real time andcalculation of an elasticity modulus profile along the examinedposterior vaginal wall. Turning the probe and using the same technique,an operator may receive vaginal tactile images and elasticity modulusprofiles along the examined anterior vaginal wall 16, as well as leftand right sides of the vagina (not shown). Tactile imaging data comingfrom the transvaginal probe may be observed in three orthogonalprojections representing examined parts of the vagina. A rotationalmotion and sliding motion of the probe 10 while exerting a load to thevaginal wall may also be used during the examination to provide acircumferential vaginal image.

Other examination techniques are also applicable for the purposes of theinvention. For example, during the examination procedure, thetransvaginal probe 10 may be moved along the vaginal axis withoutapplying pressure to vaginal walls so as to record surface pressure atrest for anterior vaginal wall 16 and posterior vaginal wall 17. Also,the transvaginal probe 10 may be used for detecting muscle strengthunder a vaginal muscular contraction when a patient is instructed tocontract appropriate vaginal muscles. The probe 10 may further be movedfrom hymen 19 to cervix 18 while applying pressure circumferentially tovaginal walls. An average pressure applied to vaginal wall may be in therange from about 1 kPa to about 12 kPa. The examination procedure may beperformed once or may be repeated several times at one or more selectedlocations. In embodiments, additional passes of the probe over one ormore locations along the vaginal walls may be conducted with increasinglevels of the pressure, for example up to 20 kPa. Obtained data may bestored in a digital format allowing a review of one, two, or threeorthogonal cross-sections selected for tactile image of vagina. Tactileimages of vagina may be used for calculating elasticity modulus atspecified locations or along selected lines and geometrical features. Inembodiments, a spacing profile may for example be calculated as a set ofdistances between anterior and posterior along the vagina in at leasttwo or more such locations.

The transvaginal probe 10 includes one or multiple pressure sensorsforming one or multiple pressure sensor arrays configured for contactingvaginal walls and cervix. As shown in FIG. 1, sensor arrays 12 and 13may be configured for a contact with opposing vaginal walls, e.g.anterior wall 16 and posterior wall 17, as well as a left side and aright side of vagina 11. Pressure sensor array 14 may be configured fora contact with cervix 18. The pressure sensor arrays may be assembled astwo-dimensional sensor arrays on the part of the surface of the probe 10adapted for contacting the vaginal tissue. The pressure-sensitivesurface of the probe 10 configured for contacting the vaginal wall mayhave a rounded shape with a radius of curvature of about 15 mm. Thepressure-sensitive surface of the pressure sensor array 14 may be flat.The motion tracking sensor 15 may be configured to record at least oneor more of the three coordinates (X, Y, Z) and/or three angles(Elevation, Rotation, Azimuth) of the transvaginal probe 10. Recordingcoordinates and angles allows calculating coordinates of all pressuresensors of the probe 10 in a coordinate system tied to pelvic floor bonyframework. An electronic unit for data acquisition may be configured torecord the pressure array readings and the motion sensor readings, sothat in combination, the sensor coordinates and sensor pressure data arerecorded at the same time and paired together for placing into 3-Dtactile image.

The pressure pattern on the surface of the vagina wall while deformed bythe probe reveals not only elasticity conditions of vaginal wall itself,but an elasticity distribution of underlying structures: higher appliedpressure reveals deeper structures surrounding vagina. The pressurepatterns on the surface of vaginal walls together with tissuedisplacement caused by deformation from the probe may be considered asdocumentation of the current elasticity state of the vaginal walls andsurrounding support structures. All acquired pressure patterns formtogether a 3-D tactile image. The 3-D tactile image of the vagina may becomposed using a spatial scalar mapping of the pressure patternsacquired at the vaginal wall under deformation. The spatial mappingtechnique involves acquisition of probe motion tracking data, which maybe transformed into spatial coordinates of each pressure sensor at thecontact surface of the vaginal wall where the pressure signals wereacquired during in the course of vaginal wall deformation. One practicalway to observe a 3-D tactile image of vagina may be to represent it bythree orthogonal cross-sections of the vagina as shown in FIG. 2. Theprimary regions of interest may be the anterior and posterior parts ofthe vagina, which are represented on the sigittal cross-section (seeSigittal plane in FIG. 2). Circumferential vaginal structures may bebetter observed in the transverse cross-section (see Transverse plane inFIG. 2). Left and right side support structures may be visualized incoronal cross-section (see Coronal plane in FIG. 2). Calculated tissueelasticity and geometrical measures may be projected on the respectivecross-section of the 3-D tactile image to assist in visualinterpretation of the examination results and comparison with referencedata. Reference data may include prior measurements for the same patientor normal elasticity distributions and normal anatomical sizes obtainedfor a plurality of patients with known clinical status. Clinicalexamples of vaginal tactile images are presented in FIG. 2 and FIG. 3.

Tissue elasticity measures such as Young's modulus (E) may be calculatedusing a number of approaches, including:

-   -   1. comparing spatial gradients in 3-D tactile images of the        vagina with the spatial gradients in 3-D tactile images for        tissue models of the vagina. Such models may be prequalified to        have known distribution of Young's moduli,    -   2. analyzing load curve for the probe during vaginal wall        deformation applying a preexisting tissue deformation model,    -   3. using mechanical inverse problem solution applied to 3-D        tactile image.

All three approaches require selection of a volume for averagingpressure gradients around the specified location where the tissueelasticity is to be calculated. Typical volume appropriate for thatpurpose may be in the range of 50-100 mm³. The first calculating methodfrom the listed above was used in exemplary results for tissueelasticity presented below.

FIG. 2 shows exemplary transverse, sagittal and coronal cross-sectionsof a 3-D tactile image of vagina for a patient with known normal pelvicfloor conditions examined with the transvaginal probe. The tactile imageof the vagina is presented in the units of pressure (kPa) according tospecified grayscale map. 3-D tactile images of the vagina may have alsocolor-scale map, such as the jet map. In embodiments, an operator usingtouchscreen capabilities of software interface may select geometricalfeatures inside shown cross-sections to be measured, displayed andrecorded in a computer-generated examination report. Selectedgeometrical features may include spacing between anterior and posteriorwalls, between left and right vaginal walls, distance between any twoselected points or size of the specified zone. The operator may alsoselect specific sites for calculation of tissue elasticity features,such as elastic modules, e.g. Young's modulus. Characteristic anatomicalmeasures may be placed in the images and tissue elasticity values(Young's moduli) may be calculated for different sites. Comparison ofdifferent locations demonstrates the distribution of tissue elasticity.The sigittal and transverse tactile image cross-sections in FIG. 2demonstrate strong anterior and posterior vaginal support withanterior-posterior spacing at distal part of about 14 mm. Young'smodulus (E) was calculated for areas specified by a rectangular: E=7 kPaat distal anterior and E=13 kPa at distal posterior sections of vaginarespectively. Right side of vaginal distal part demonstrated E=10 kPa(see Transverse plane in FIG. 2).

FIG. 3 presents exemplary three orthogonal cross-sections of 3-D tactileimage for a patient having a prolapse condition confirmed by physicalexamination. Significant difference can be observed in tissue elasticityand anatomy relatively the normal conditions shown in FIG. 2. In thisclinical case, elasticity modulus was determined as E=1.8 kPa at distalanterior and E=1.5 kPa at distal posterior sections respectively. Leftside of vaginal distal part demonstrated E=2.8 kPa (Transverse plane inFIG. 3). The anterior-posterior spacing at distal part of vagina wasmeasured as 37 mm (Sagittal plane in FIG. 3).

FIG. 4 is an illustration of calculating elasticity modulus profiles forthe anterior and posterior vaginal walls. The sagittal cross-section of3-D tactile image of a patient is presented in FIG. 4A. The whiterectangles in FIG. 4A denote cross-sections with an average size of 5mm×4 mm×5 mm used for a tactile gradient calculation. The tactilegradient may be calculated in the direction orthogonal to the vaginalwall boundary defined at the constant pressure level of about 1 kPa.Based on experimentation with pelvic floor models built with knownYoung's modulus distribution of elastic silicone, empirical equationsmay be derived for transforming the tactile gradient value into Young'smodulus. Moving the averaging volume along a predetermined line such asthe dashed lines in FIG. 4A and calculating Young's modulus along thesame line allows building of the elasticity modulus profile for theanterior vaginal wall (FIG. 4B) and posterior vaginal wall (FIG. 4C). A5 mm step may be used along the line for the elasticity modulus profilecalculation. The line for elasticity profile calculation may be selectedalong any part of 3-D tactile image of the vagina, e.g. along the leftand right vaginal walls. For characterization of elasticity conditionsof the vagina and its support structures, a set of locations andthreshold values of elasticity modulus for these locations may beintroduced, e.g. for middle anterior, middle posterior, distal anteriorand distal posterior sections of vagina.

FIG. 5 is an exemplary illustration of calculating spacing profile forthe anterior-posterior vaginal walls. The sagittal cross-section of 3-Dtactile image of a patient is presented in FIG. 5A. The dashed linesalong the anterior and posterior vaginal walls are iso-linescorresponding to a constant deformation pressure of 1 kPa; these linesdefine the boundaries of the vaginal walls at rest. The distancesbetween the anterior and posterior walls boundaries, measured ingenerally orthogonal direction to the vaginal axis, define the spacingprofile between the walls. At least two such distances are needed toestablish a spacing profile. Greater number of distances improves theaccuracy of the spacing profile. In embodiments, moving with a certainstep (such as 5 mm) the location along the vaginal axis where theanterior-posterior distance is calculated allows building ananterior-posterior spacing profile (see FIG. 5B). The spacing profilemay also be calculated for the left-right sides of the vagina. Forcharacterization of anatomical conditions of the vagina and its supportstructures, a set of locations and spacing threshold values for theselocations may be introduced, e.g. for proximal, middle and distalsections of vagina.

FIG. 6 is a flow chart illustrating one method for assessment of pelvicorgan conditions affecting the vagina, in particular assessing a risk ofvaginal organ prolapse development. The transvaginal probe of theinvention may be used to assess the risk of development of the pelvicorgan prolapse. The method of the invention is based on the notion thatelasticity of the pelvic floor tissues starts to change well before theclinically-evident prolapse can be diagnosed. Early warning of theimpending prolapse can therefore be obtained by recording the tactileimage of the vaginal tissues and detecting the change in elasticity ascompared to a predefined normal threshold. Knowing the degree ofdeviation of the measured values from the threshold may allow estimatinga risk of vaginal organ prolapse development and may allow predicting atimeframe for its development.

In embodiments, methods for assessment of pelvic organ conditionsaffecting a vagina such as a risk of pelvic organ prolapse developmentmay include the following steps:

(a) conducting examination of vagina by deforming vagina along ananterior vaginal wall and along a posterior vaginal wall using atransvaginal probe as described above;(b) obtaining pressure patterns and coordinates corresponding theretofor portions of vagina examined with the transvaginal probe, a tactileimage of the vagina may then be generated;(c) calculating using the pressure patterns and coordinates at least oneor both anterior elasticity modulus profile and posterior elasticitymodulus profile, these elasticity modulus profiles being defined by atleast two or more locations spaced apart in the respective portion ofvagina examined with the transvaginal probe;(d) calculating at least two or more distances between the anteriorvaginal wall and the posterior vaginal wall along the vagina whichcumulatively define a spacing profile of the vagina; and(e) estimating a risk of POP development by comparing at least oneelasticity modulus profile at the two or more locations againstrespective predetermined elasticity modulus thresholds for the samelocations as well as by comparing the spacing profile against respectivepredetermined distance thresholds.

The values of thresholds may be defined from clinical data for aplurality of patients, in particular, for patients with known clinicaldiagnosis established by different modalities. The locations forcomparing elasticity modulus may be selected to include distal anterior,distal posterior, middle anterior and middle posterior sections ofvagina. These locations are known to closely correspond with the pelvicfloor support structure. The locations for comparing distances betweenthe anterior and posterior vaginal walls may be selected to includeproximal, middle and distal sections of vagina. In embodiments, the riskof POP development may be designated as elevated if the measuredelasticity falls below the following elasticity modulus thresholds 4 kPafor the distal anterior, 3.5 kPa for the distal posterior, 8 kPa for themiddle anterior and 6 kPa, for the middle posterior sectionsrespectively. The step of calculating a spacing profile may furtherinclude calculating vaginal wall coordinates along the vagina at theconstant pressure level of about 1 kPa so as to establish physicallocations (boundaries) of the vaginal walls at rest. In embodiments,comparison of spacing profile may be done against the distancethresholds of about 15 mm for middle section and about 25 mm for distalsection of the vagina respectively. Elevated risk of POP development isdetected if the spacing profile exceeds these thresholds.

In embodiments, the step of estimating the risk of POP development mayalso include an adjustment based on at least one or morepatient-specific factors. Such patient-specific factors may includepatient's age, history of childbirth, history of chronic straining toempty bowel or bladder, status of menopause, obesity, history of priorhysterectomy, history of prior pelvic surgery, history of strenuousactivity, smoking status, and alcohol use status.

FIG. 7 is a flow chart illustrating a method for assessment of pelvicorgan conditions affecting the vagina, in particular estimating anextent of pelvic support tissue impairment or damage after childbirth.The transvaginal probe of the invention may be used to estimate thetraumatic damage. The method is based on a notion that elasticity of thepelvic floor tissues is a good predictor of vaginal tissue deviationsfrom normal conditions including disruptions of support muscles, fasciatissue and ligaments. Knowledge of the degree of tissue damage, which ischaracterized by elasticity deviation, as well as damage zone size andlocation, may lead to an effective treatment or an interventionprocedure.

In embodiments, methods for assessment of pelvic organ conditionsaffecting a vagina may include the following steps:

(a) conducting examination by deforming the vagina along an anteriorvaginal wall, along a posterior vaginal wall, along a left side ofvagina and along a right side of vagina using a transvaginal probe—asdescribed above in greater detail;(b) obtaining pressure patterns and coordinates corresponding theretofor portions of vagina examined with the transvaginal probe;(c) calculating from the pressure patterns and coordinates at least oneelasticity modulus profile defined by at least two or more locationsspaced apart along vagina. Calculated elasticity modulus profile mayinclude an anterior elasticity modulus profile, a posterior elasticitymodulus profile, a left side elasticity modulus profile and a right sideelasticity modulus profile;(d) calculating from the same pressure patterns and coordinates at leastone of an anterior-posterior spacing profile or a left-right spacingprofile. The anterior-posterior spacing profile may be defined by atleast two or more distances between the anterior vaginal wall and theposterior vaginal wall. The left-right spacing profile may be defined byat least two or more distances between the left side and the right sideof the vagina; and(e) estimating extent of pelvic support tissue impairment or damageafter childbirth by comparing at least one or more elasticity modulusprofiles against normal values such as for example correspondingelasticity modulus profile or profiles obtained for patients known tohave no pelvic support tissue impairment or damage. The extent of tissueimpairment or damage may be further estimated by comparing at least oneor more of the calculated spacing profiles against normal values, forexample against a corresponding spacing profile obtained for patientsknown to have no pelvic support tissue impairment or damage.

The step of estimating an extent of pelvic floor organ traumatic damageafter childbirth may further include detection of a traumatic tissuedamage zone and calculating a characteristic zone size of the traumatictissue damage zone as well as elasticity modulus for the traumatictissue damage zone using for example one of three approaches listedabove.

FIG. 8 is a flow chart illustrating a method for assessment of pelvicorgan conditions affecting the vagina, in particular estimating animprovement after an interventional procedure. Using the methods of theinvention, the transvaginal probe of the invention may be used toestimate the improvement. The method of the invention is based on anotion that elasticity of the pelvic floor tissues is a good predictorof vaginal tissue conditions because pelvic organ support systemincluding muscles, fascia tissues and ligaments is a biomechanicalsystem responsible for vital physiological processes. One of the basicaims of pelvic floor reconstructive surgery is to correct anatomicaldeviations by restoring strength and elasticity of pelvic organ supportstructures. Knowledge of the vaginal tissue and support structureelasticity in-vivo after the surgery may allow quantitativecharacterization of its outcome.

The interventional procedure in which the methods of the invention areapplicable may include a variety of procedures such as tissueregeneration resulting from injecting muscle cells, tissue regenerationresulting from injecting stem cells, surgical repair of the vaginalwall, surgical repair of muscle structures, surgical implantation of anartificial supporting structure, and surgical implantation of anartificial structure inside a muscle.

With regard to the elastic properties of the vaginal wall, the methodsof the invention may also be useful when assessing the vaginal wallabnormalities including cancerous or pre-cancerous lesions. Vaginal andvulvar cancers are particularly difficult to detect without theapplication of invasive testing methods such as acetic acid, coloposcopyor direct biopsy techniques. Examination by any available means, evenfor screening purposes, is highly dependent on physician skill, level ofsuspicion for an abnormality and limitations of performing the exam. Theuse of methods of the invention for tissue elasticity quantificationwith the transvaginal probe may solve this problem because canceroustissue is known to have increased hardness.

Although the invention herein has been described with respect toparticular embodiments, it is understood that these embodiments aremerely illustrative of the principles and applications of the presentinvention. It is therefore to be understood that numerous modificationsmay be made to the illustrative embodiments and that other arrangementsmay be devised without departing from the spirit and scope of thepresent invention as defined by the appended claims.

1. A method for assessment of pelvic organ conditions affecting avagina, said method comprising the steps of: (a) conducting examinationof said vagina by deforming said vagina along an anterior vaginal walland along a posterior vaginal wall using a transvaginal probe; (b)obtaining pressure patterns and coordinates corresponding thereto forportions of vagina examined with said transvaginal probe; (c)calculating at least one of anterior elasticity modulus profile orposterior elasticity modulus profile, said elasticity modulus profilesdefined by at least two locations spaced apart in said respectiveportion of vagina examined with said transvaginal probe; (d) calculatingat least two distances between said anterior vaginal wall and saidposterior vaginal wall along said vagina defining a spacing profiletherefor; and (e) estimating a risk of pelvic organ prolapse developmentby comparing said at least one said elasticity modulus profile at saidtwo locations against respective predetermined elasticity modulusthresholds for said same two locations and by comparing said spacingprofile against respective predetermined distance thresholds.
 2. Themethod as in claim 1, wherein said locations are selected from a groupconsisting of distal anterior, distal posterior, middle anterior andmiddle posterior sections of said vagina.
 3. The method as in claim 2,wherein said risk of pelvic organ prolapse development is defined aselevated if said calculated elasticity modulus is below about 4 kPathreshold for distal anterior, 3.5 kPa threshold for distal posterior, 8kPa threshold for middle anterior and 6 kPa threshold for middleposterior sections of said vagina respectively.
 4. The method as inclaim 1, wherein said locations for calculating distances betweenanterior and posterior vaginal walls are selected from including groupconsisting of proximal, middle and distal sections of said vagina. 5.The method as in claim 1, wherein said step (d) further includes usingsaid pressure patterns and coordinates to determine vaginal wallcoordinates along the vagina when a constant pressure of about 1 kPa wasapplied by said transvaginal probe.
 6. The method as in claim 5, whereinsaid risk of pelvic organ prolapse development is defined as elevated ifsaid calculated distance between said anterior vaginal wall and saidposterior vaginal wall is above about 15 mm in said distal section ofsaid vagina or above about 25 mm in said middle section thereof.
 7. Themethod as in claim 1, wherein said step (e) further includes adjustingsaid risk using at least one patient-specific factor, saidpatient-specific factor is selected from a group consisting of patientage, history of childbirth, history of chronic straining to empty bowelor bladder, status of menopause, obesity, history of prior hysterectomy,history of prior pelvic surgery, history of strenuous activity, smokingstatus, and alcohol use status.
 8. A method for assessment of pelvicorgan conditions affecting a vagina, said method comprising the stepsof: (a) conducting examination of said vagina by deforming said vaginaalong an anterior vaginal wall, along a posterior vaginal wall, along aleft side of said vagina and along a right side of said vagina using atransvaginal probe; (b) obtaining pressure patterns and coordinatescorresponding thereto for portions of vagina examined with saidtransvaginal probe; (c) calculating from said pressure patterns andcoordinates at least one elasticity modulus profile defined by at leasttwo locations spaced apart in said vagina, said at least one elasticitymodulus profile is selected from a group consisting of anteriorelasticity modulus profile, posterior elasticity modulus profile, leftside elasticity modulus profile and right side elasticity modulusprofile; (d) calculating from said pressure patterns and coordinates atleast one of an anterior-posterior spacing profile or a left-rightspacing profile, said anterior-posterior spacing profile is defined byat least two distances between said anterior vaginal wall and saidposterior vaginal wall, said left-right spacing profile is defined by atleast two distances between said left side and said right side of saidvagina; and (e) estimating extent of pelvic support tissue impairment ordamage after childbirth by comparing said at least one elasticitymodulus profile with a corresponding elasticity modulus profile obtainedfor patients known to have no pelvic support tissue impairment or damageand by comparing said at least one calculated spacing profile with acorresponding spacing profile obtained for patients known to have nopelvic support tissue impairment or damage.
 9. The method as in claim 8,wherein said step (e) further includes detecting and sizing of atraumatic tissue damage zone.
 10. The method as in claim 9, wherein saidstep (e) further includes calculating elasticity modulus for saidtraumatic tissue damage zone.
 11. A method for assessment of pelvicorgan conditions affecting a vagina, said method comprising the stepsof: (a) conducting examination of said vagina before and after aninterventional procedure by deforming said vagina along an anteriorvaginal wall, along a posterior vaginal wall, along a left side of saidvagina and along a right side of said vagina using a transvaginal probe;(b) obtaining pressure patterns and coordinates corresponding theretofor portions of vagina examined with said transvaginal probe before andafter said interventional procedure; (c) calculating from said pressurepatterns and coordinates at least one elasticity modulus profile definedby at least two locations spaced apart in said vagina, said at least oneelasticity modulus profile is selected from a group consisting ofanterior elasticity modulus profile, posterior elasticity modulusprofile, left side elasticity modulus profile and right side elasticitymodulus profile; (d) calculating from said pressure patterns andcoordinates at least one of an anterior-posterior spacing profile or aleft-right spacing profile, said anterior-posterior spacing profile isdefined by at least two distances between said anterior vaginal wall andsaid posterior vaginal wall, said left-right spacing profile is definedby at least two distances between said left side and said right side ofsaid vagina; and (e) estimating an improvement after said interventionalprocedure by comparing said at least one elasticity modulus profileobtained before said interventional procedure and after thereof, sameimprovement is further estimated by comparing said at least one spacingprofile obtained before said interventional procedure and after thereof.12. The method as in claim 11, wherein said interventional procedure isselected from a group consisting of: tissue regeneration resulting frominjecting muscle cells, tissue regeneration resulting from injectingstem cells, surgical repair of the vaginal wall and surrounding supporttissues, surgical repair of muscle structures, surgical implantation ofan artificial supporting structure, and surgical implantation of anartificial structure inside a muscle.